Detecting the presence and characteristics of particular substances and/or combinations of substances that are difficult to inspect can provide entities interested in the control and monitoring of such substances with information critical to those entities' operations. Technology capable of such detection and characterization finds applicability in many areas, such as in, linear displacement measurement devices, position measurement, pressure analysis, land mine detection, fluid/soil contamination, fluid/gas level detection, substance composition analysis, geological mapping/imaging, and in a myriad of storage, monitoring, and processing applications.
The technologies that have been developed and applied to such detection and characterization are as diverse as their applications and include, for example, mechanical/electromechanical sensors (e.g., floats), sonic/ultrasonic sensors, radar (e.g., ground penetrating radar), time domain reflectometry sensors (“TDR”), x-ray sensors, capacitive level sensors, etc. These technologies can exhibit shortcomings that mitigate their usefulness such as, for example, floats that can be unreliable particularly in multi-fluid and/or corrosive environments; sonic/ultrasonic sensors whose acoustic signals may reflect off of foamy material or container walls and fail to capture fluidic surfaces and boundaries; radar sensors may be expensive, complex, bulky, and/or may exhibit limited resolution; TDR sensors may exhibit excessive ringing and thereby limit short range detection and may require different designs when used with different dielectric substances due to changes in reflection amplitude; x-ray sensors may fail to differentiate between similar substances; and capacitive level sensors may not operate accurately due to nonlinear dielectric properties of a substance and may fail to provide desirable information about a particular mixture. Accordingly, entities interested in residential, commercial, industrial, medical, scientific, military, and/or other applications of substance characterization technology have a continuing interest in further developing these technologies to more accurately and flexibly meet their control and monitoring objectives.